Advocates claim the approach helps babies develop motor skills, become less picky eaters and possibly have a lower risk of obesity later in life because they are controlling how much they eat.

But there are also concerns, including the potential for choking, said senior study author Rachael Taylor, a research associate professor at the University of Otago, in New Zealand.

To dig into the question, she and her colleagues randomly assigned 206 mothers to either introduce solid foods the traditional way or try the baby-led approach. Moms in that second group were given education on how to safely let their babies feed themselves.

For one, the baby should be able to sit up; Taylor's team "strongly encouraged" parents in the baby-led group to delay solids until the age of 6 months.

Second, any food should pass the "squish test," said Taylor.

"Make sure that you can squash the foods you offer your baby on the roof of your mouth," she said. That means certain soft cooked vegetables would be OK, for instance, but raw vegetables would be out -- as would raw apple or other fruits that are hard or contain seeds.

And no matter what the food, Taylor said, parents should always supervise while their baby eats.

In this study, babies who fed themselves were no more likely to choke than those who were spoon-fed. Between the ages of 6 and 8 months, 35 percent of all babies in the study choked at least once, based on parents' reports -- with no significant difference between the two groups.

On the other hand, the study found that babies in both groups were commonly given foods that pose a choking risk: More than half were given risky foods at the age of 7 months, and nearly all were given them at 12 months.

Raw vegetables and hard crackers were among the most common offenders.

"We were very surprised that so many babies were being offered foods that could pose a choking hazard," Taylor said.

This suggests that many parents need more information on how to safely introduce solid foods, according to Taylor. "But they also need education on the importance of always being with their child when they're eating, and knowing what to do if their child chokes," she added.

Dr. Anthony Porto, a pediatrician who was not involved in the study, agreed.

It's always a good idea for expectant parents to take an infant and child CPR class, which typically includes instruction on how to handle choking, according to Porto. He is associate clinical chief of pediatric gastroenterology at Yale University.

As for baby-led feeding, he offered a few precautions.

For one, parents in this study had professional guidance on how to do it, said Porto.

"This was carefully designed, and families were well-supported through the process," he said. "So I'm not sure how reflective this is of what parents are doing in the 'real world.' "

Plus, choking is not the only issue when introducing solids, Porto pointed out. Parents should also consider the nutrients in the foods they're offering.

In general, child health experts recommend that babies be exclusively breast-fed for the first six months, then have "complementary" foods gradually added to their diets. Because breast milk has little iron, Porto said, pediatricians usually recommend introducing a food source with the mineral -- such as iron-fortified baby cereal or baby food containing meat.

Taylor said her team is currently reviewing whether babies in their study face any increased risk of slow growth or iron deficiency.

In an earlier study, she said, infants in the baby-led group seemed to have lower intakes of iron, zinc and vitamin B12. But at this point, she added, there's no evidence they're at risk of nutrient deficiencies.

At the same time, though, it's still unclear whether baby-led weaning has special advantages, either, Porto pointed out. "There's no definitive data that it decreases obesity risk, for example," he said.

For now, Porto suggests that parents who are interested in the approach get advice from their pediatrician or a dietitian on how to go about it.

"You should try to do what's best from a safety standpoint, an allergy standpoint, and a nutrition standpoint," he said.

The findings were published online Sept. 19 in the journal Pediatrics.